JP6057509B2 - Light oil fuel composition - Google Patents

Description

  The present invention relates to a light oil fuel composition used for a diesel engine or the like.

    In light oil fuel compositions used for diesel engines and the like, low temperature performance is adjusted by using cloud points, pour points, and the like as an index in consideration of use in cold regions and winter seasons. Many methods for obtaining desired low-temperature performance have been proposed.

  For example, in Japanese Patent Application Laid-Open No. 2008-1111082, the weight ratio of the total content of linear paraffins having 15 to 18 carbon atoms to the total content of linear paraffins having 10 to 14 carbon atoms is 0.5 to 1.5. In addition, the weight ratio of the total content of linear paraffins having 15 to 18 carbon atoms to the total content of linear paraffins having 19 to 25 carbon atoms is set to 0.5 to 1.5. A technique for reducing the amount of chain paraffin and enhancing the effect of the additive used for improving the low temperature properties is disclosed.

  Japanese Patent Application Laid-Open No. 2005-220330 discloses a linearity obtained by determining the slow cooling cloud point (X) from −30.0 to −15.0 ° C. and the normal paraffin content of 18 to 25 carbon atoms in the light oil composition. Normal paraffin having a slope (Y) of the regression line of 0.18 or less, an index (Z) represented by a predetermined formula having X and Y as variables, 1.5 or more, and a carbon number in the composition of 18 or more By reducing the sulfur content to 3.4 mass% or less, there is a technique that satisfies the practical performance and the exhaust gas purification ability without causing filter clogging at a low temperature while suppressing the sulfur content to 50 mass ppm or less. It is disclosed.

JP 2008-111082 A Japanese Patent Application No. 2005-220330

  In recent years, with changes in the social situation, the characteristics of light oil fuel compositions and the points to be considered in the manufacturing method have also changed. Specifically, the content of sulfur and the increase in the mixing ratio of cracked light oil to the light oil desulfurization equipment accompanying the decrease in demand for heavy oil can be mentioned. And with these environmental changes and changes in the demand structure of fuel oil, there are cases where conventional technology cannot be used to maintain the low temperature performance of diesel oil. There is a possibility that a sufficient effect cannot be obtained with an additive (low temperature fluidity improver: CFI) used for improving low temperature properties. For this reason, a new index is required in response to environmental changes.

  One of the reasons why the conventional technology cannot be used for maintaining the low temperature performance of light oil is that most of the technology pays attention to the properties and precipitation amount of normal paraffin (wax). On the other hand, in order to improve the low-temperature performance of the light oil fuel composition while sufficiently responding to changes in the social situation, the present inventor has increased the mixing ratio of the cracked light oil with the decrease in the sulfur content. In addition to the properties and amount of precipitation, substances that contribute to the amount of wax precipitated at low temperatures, that is, aromatics that are abundant in cracked gas oil, and the composition of naphthene that is produced by hydrogenating aromatics in a desulfurization unit It was found that it is necessary to pay attention to the content.

  An object of the present invention is to provide a light oil fuel composition having a low-temperature property sufficient for use as a fuel for vehicles while responding to a decrease in the sulfur content and an increase in the mixing ratio of cracked light oil.

  The light oil fuel composition of the present invention has a normal paraffin content of 19 to 23 carbon atoms of 7.5 mass% or less, cycloparaffins of 34 mass% or more, aromatic content of 18 vol% or more, and sulfur content of 10 massppm or less. System low temperature fluidity improver.

  In the present invention, the EV low temperature fluidity improver is an ethylene-unsaturated ester copolymer. An ethylene-vinyl acetate copolymer (EVA type) is one of the representative examples. The EVA acetate group (acetic acid group) has two carbon atoms, but a low temperature fluidity improver substituted with an alkyl group having an appropriate carbon number in place of the methyl group in the acetate group is also possible. The addition amount is preferably 50 to 500 mg / L, and particularly preferably 100 to 500 mg / L.

Alkylbenzenes is at least 10 mass%, also Ru der 2 or more rings cycloparaffins or more 11mass%.

  In the present invention, cycloparaffins mean alicyclic hydrocarbons, including monocyclic, bicyclic and tricyclic, and those substituted with an alkyl group. Bicyclic cycloparaffins mean bicyclic alicyclic hydrocarbons, including those substituted with an alkyl group.

  Further, in the present invention, alkylbenzenes are those in which a single ring aromatic is substituted with an alkyl group, and pentamethylbenzene, hexamethylbenzene, 1-ethyl-3-methylbenzene, trimethylbenzene derivatives, 1-ethyl- Examples include, but are not limited to, 3,5-dimethylbenzene, 1-methyl-4-propylbenzene, 2-methyl-1,3-dimethylbenzene.

  ADVANTAGE OF THE INVENTION According to this invention, the light oil fuel composition provided with the low-temperature property sufficient for the fuel of a vehicle can be provided, respond | corresponding to the fall of content of sulfur, and the increase in the mixing ratio of cracked light oil.

  Although it is well known that the normal paraffin content called the wax content greatly affects the low-temperature performance of the light oil fuel composition, the present inventor also supplies fuel to the diesel engine among the normal paraffins. Focusing on the matter that precipitates on the filter installed in the system and causes clogging, the composition was analyzed. The result of the analysis is shown in FIG. In collecting the wax to be analyzed, first, the light oil fuel composition is placed in a thermostatic bath at 25 ° C., and rapidly cooled to a temperature 5.0 ° C. higher than the cloud point measured in advance for the light oil fuel composition. The solution was gradually cooled to −5.0 ° C. at 1.0 ° C./h. And the precipitated wax was extract | collected using the suction filtration apparatus. Glass fiber filter paper (GF series: GF / A: 1.6 μm) was used for wax collection. Further, the light oil fuel composition remaining in the collected wax was removed using 2-butanone. The obtained wax content was analyzed by gas chromatography.

  As shown in FIG. 1, normal paraffin in light oil is widely distributed from C9 to C30 and has peaks from C16 to C18. On the other hand, the carbon distribution of the wax that causes clogging mainly occupies 19 to 23, and the present inventor adjusts the normal paraffin content of 19 to 23 carbons based on this analysis result. And found that good low-temperature fluidity can be secured. Moreover, when the relationship between the normal paraffin having 19 to 23 carbon atoms and the composition and low-temperature fluidity of other light oil fuel compositions was examined, not only the normal paraffin content having 19 to 23 carbon atoms but also aromatic components and alkylbenzenes and It has been found that the composition and ratio of cycloparaffins and bicyclic cycloparaffins also affect low temperature performance. And it was in the social situation by combining a specific additive with a base material that appropriately controlled the amount of wax having a specific carbon number, aromatic content including alkylbenzenes, and cycloparaffins including bicyclic cycloparaffins. It was found that appropriate low-temperature fluidity can be secured even under circumstances. The present invention is based on these new findings by the present inventors.

It is a graph which shows carbon number distribution of normal paraffin in wax in comparison with carbon number distribution of normal paraffin in light oil fuel composition.

In the light oil fuel composition of the present invention, one or more light oil base materials are treated with a secondary device such as a desulfurization device so as to have a specific property defined by the light oil fuel composition finally obtained. Regardless of the sulfur content of 10 massppm or less or the sulfur content value, one or two or more light oil base materials can be mixed and prepared.
For example, a kerosene fraction and a light oil fraction obtained by atmospheric distillation of crude oil, and a desulfurized kerosene and a desulfurized gas oil obtained by desulfurizing them can be used. A light oil fuel composition having a sulfur content of 10 mass ppm or less obtained by mixing and desulfurizing a light oil fraction obtained from an atmospheric distillation apparatus and cracked light oil at an appropriate ratio can also be used. Note that cracked diesel oil refers to diesel oil distilled from an upgrade process of heavy oil such as directly-desulfurized diesel oil obtained from direct desulfurization equipment, indirectly-desulfurized diesel oil obtained from indirect desulfurization equipment, or light cycle oil obtained from fluid catalytic cracking equipment. The fraction is a fraction, and it is preferable to make the mixing ratio as high as possible in accordance with recent social demands.
Furthermore, light oils obtained by hydrotreating them for improving the hue can also be used. That is, desulfurizer raw material types and ratios so that normal paraffins, cycloparaffins, aromatics, bicyclic cycloparaffins, and alkylbenzenes having 15 to 23 carbon atoms in desulfurized light oil after the desulfurizer treatment are in an appropriate amount. It is possible to use those obtained by adjusting various desulfurization conditions so that these substances that disappear and are generated by the reaction in the desulfurization apparatus are within an appropriate range in the final product.
In addition, the oil refined secondary equipment regardless of whether or not the gas oil after desulfurization satisfies or does not satisfy the proper amount of normal paraffins, cycloparaffins, aromatics, bicyclic cycloparaffins and alkylbenzenes having 15 to 23 carbon atoms. It is also possible to satisfy the above-mentioned appropriate amount by using, as a base material, a gas oil equivalent oil, hydrocracked gas oil, Fischer-Tropsch synthetic oil, etc. distilled from

  The normal paraffin content having 19 to 23 carbon atoms is 7.5 mass% or less. If the temperature is higher than that, it is not preferable because the low-temperature properties are deteriorated such that the filter in the fuel supply path to the diesel engine is likely to be clogged when starting at a low temperature. 7.0 mass% or less is more preferable, and 6.0 mass% or less is still more preferable. However, the normal paraffin content having 19 to 23 carbon atoms is preferably as small as possible from the viewpoint of improving the low-temperature properties, but from the viewpoint of the cetane index, it is necessary to be 4.0 mass% or more, preferably 5.0 mass% or more. is there.

  Cycloparaffins are 34 mass% or more. 35 mass% or more is more preferable, and 36 mass% or more is still more preferable. Moreover, bicyclic cycloparaffins are 11 mass% or more, 12 mass% or more is preferable, More preferably, it is 13 mass% or more.

  The aromatic content is 18 vol% or more, preferably 20 vol% or more, and more preferably 23 vol% or more. Moreover, 10 mass% or more of alkylbenzenes is preferable, 11 mass% or more is more preferable, and 15 mass% or more is further more preferable. However, if the aromatic content is too large, the cetane number decreases, causing problems such as an increase in particulate matter in automobile exhaust gas, so 28 vol% or less is preferable.

  The sulfur content needs to satisfy the JIS K 2204 standard determined in consideration of the influence on the environment, that is, 10 mass% or less.

  The light oil fuel composition of the present invention can greatly improve the low temperature properties of the substrate by adding an EV-based low temperature fluidity improver. As the EV low temperature fluidity improver, for example, Carriol KA-701 (manufactured by Sanyo Kasei Co., Ltd.) and R570 (manufactured by Infinium Co., Ltd.) are suitable. If necessary, other additives such as a lubricity improver may be added to prevent wear of antioxidants, fuel supply pump parts, and the like.

"Example 1"
A straight-run gas oil fraction having a boiling range of 181 to 371 ° C is 85 vol%, a light cycle oil having a boiling range of 145 to 372 ° C distilled from a fluid catalytic cracker is 10 vol%, and a distillate from an indirect desulfurizer having a boiling range of 170 to 365 ° C. Desulfurization of mixed oil with 5 vol% of degassed oil while being put out using a commercially available desulfurization catalyst until the sulfur content becomes 10 massppm or less under conditions of liquid space velocity 1.0, hydrogen partial pressure 5 MPa, hydrogen oil ratio 150 NL / L A light oil fuel composition obtained by adding 200 mass ppm of an EV-based low-temperature fluidity improver (CFI1) described later to light oil obtained by processing.
"Example 2"
Using a commercially available desulfurization catalyst, 90% by volume of a straight-run gas oil fraction having a boiling range of 181 to 362 ° C. and 10% by volume of light cycle oil having a boiling range of 145 to 374 ° C. distilled from a fluid catalytic cracking unit is used as a liquid space A light oil fuel composition obtained by adding 200 massppm of the above CFI1 to light oil obtained by desulfurization treatment until the sulfur content becomes 10 massppm or less under the conditions of a speed of 1.5, a hydrogen partial pressure of 4 MPa, and a hydrogen oil ratio of 150 NL / L.
"Comparative Example 1"
Using a commercially available desulfurization catalyst, a liquid space is obtained by mixing 98 vol% of a straight-run gas oil fraction having a boiling point range of 181 to 362 ° C and 2 vol% of a light cycle oil having a boiling range of 145 to 374 ° C distilled from a fluid catalytic cracker. A light oil fuel composition obtained by adding 200 massppm of the above CFI1 to light oil obtained by desulfurization treatment until the sulfur content becomes 10 massppm or less under the conditions of a speed of 1.5, a hydrogen partial pressure of 4 MPa, and a hydrogen oil ratio of 150 NL / L.
“Comparative Example 2”
Using a commercially available desulfurization catalyst, a liquid space is obtained by mixing 95 vol% of a straight-run gas oil fraction having a boiling point range of 181 to 376 ° C and 5 vol% of a light cycle oil having a boiling range of 145 to 372 ° C distilled from a fluid catalytic cracker. A light oil fuel composition obtained by adding 200 massppm of the above CFI1 to light oil obtained by desulfurization treatment until the sulfur content becomes 10 massppm or less under the conditions of a speed of 1.0, a hydrogen partial pressure of 5 MPa, and a hydrogen oil ratio of 150 NL / L.
“Comparative Example 3”
A diesel fuel composition obtained by adding 200 mass ppm of a surfactant-based low-temperature fluidity improver (CFI2) described later to the diesel oil obtained in Example 1.
“Comparative Example 4”
A light oil fuel composition obtained by adding 200 mass ppm of a WAX dispersant-based low-temperature fluidity improver (CFI3) described later to the light oil obtained in Example 1.
"CFI1"
R570 (manufactured by Infinium)
"CFI2"
FPD-779N (Toho Chemical Co., Ltd.)
"CFI3"
Cariole FD-391 (manufactured by Sanyo Chemical Co., Ltd.)

In addition, each property shown in Table 1 is shown below.
“Density (@ 15 ℃)”
Density at 15 ° C. measured by JIS K 2249 “Crude oil and petroleum products—Density test method and density / mass / volume conversion table”.
"Kinematic viscosity (@ 30 ° C)"
Kinematic viscosity at 30 ° C. measured by JIS K 2283 “Crude oil and petroleum products—Kinematic viscosity test method and viscosity index calculation method”.
"Sulfur"
Sulfur content obtained by JIS K 2541-2 "Crude oil and petroleum products-Sulfur content test method Part 2: Micro coulometric titration method".
"Flash point"
Flash point obtained by JIS K 2265-3 "How to determine flash point-Part 3: Penschramtens sealing method".
“Residual carbon content of 10% residual oil”
Residual carbon content of 10% residual oil obtained by JIS K 2270 “Crude oil and petroleum products—Test method for residual carbon content”.
"Cetane index"
It means a cetane index measured according to JIS K 2280 “Petroleum products—fuel oil—octane number and cetane number test method and cetane index calculation method 8. Method for calculating cetane index using 4-variable equation”.
"Distillation properties"
Distillation properties obtained by JIS K 2254 "Petroleum products-Distillation test method".
"Total saturation"
Paraffin content measured by JPI-5S-49-97 "Petroleum products-Hydrocarbon type test method-High performance liquid chromatograph method".
`` Aromatic content total ''
Sum of 1-ring aromatics, 2-rings aromatics and 3 or more-rings aromatic hydrocarbons measured by JPI-5S-49-97 "Petroleum products-Hydrocarbon type test method-High performance liquid chromatograph method" .
"C19-23 normal paraffin content"
Using a gas chromatographic method in accordance with ASTM D 2887 “Standard Test Method for Boiling Range Distribution of Petroleum Fraction by Gas Chromatography”, the carbon content obtained from each carbon content was obtained from the carbon content obtained by carbon chromatography. That is, the retention time was examined using a mixture of normal paraffins having different carbon numbers as a standard, and the content of normal paraffins was determined from the peak area values of normal paraffins. The sum of the chromatogram area values of the peaks between the normal paraffin peaks was determined as the content of isoparaffin having N carbon atoms. Since the gas chromatography detector is a flame ionization detector (FID), the measurement sensitivity is proportional to the carbon number of paraffin. Therefore, taking this sensitivity into consideration, the content molar ratio was determined from the area value, and finally each mass ratio was determined.
The type of column in the gas chromatographic method is HP5 (length: 30 m, inner diameter: 0.32 mm, liquid layer thickness: 0.25 μm), and each analysis condition is as follows.
Column tank temperature rising condition: 35 ° C. (5 minutes) → 10 ° C./minute (temperature rising) → 320 ° C. (11.5 minutes)
Sample vaporization chamber condition: constant 320 ° C. split ratio 150: 1
Detector section: 320 ° C
"Pour point"
Pour point obtained by JIS K 2269 “Pour point of crude oil and petroleum products and cloud point test method of petroleum products”.
"Cloud point"
Cloud point obtained by JIS K 2269 “Pour point of crude oil and petroleum products and cloud point test method of petroleum products”.
"Clogging point"
A clogging point obtained by JIS K 2288 "Petroleum products-light oil-clogging point test method".
"Cycloparaffins, naphthenebenzenes, alkylbenzenes"
For the analysis of cycloparaffins, naphthenebenzenes, and alkylbenzenes, a GC system consisting of a gas chromatography with HP-6890N type FI-MS detector manufactured by Agilent Technology and a JMS-T100GC time-of-flight mass spectrometer manufactured by JEOL is used. Then, a correction graph was prepared with the analytical strength of the normal paraffin standard sample, and the measured data was corrected with the correction graph, and then the respective strength ratios were determined with the overall strength being 100 mass%.
The column type in the gas chromatogram method is DB-5 (length: 30 m, inner diameter: 0.25 mm, liquid layer thickness: 0.25 μm), and each analysis condition is as follows.
Column tank temperature rising condition: 30 ° C. (5 minutes) → 20 ° C./minute (temperature rising) → 300 ° C. (27 minutes)
Sample vaporizing chamber conditions: 300 ° C constant Splitless detector: 250 ° C
Solvent: hexane Solvent waiting time: 3 minutes Collection range: 25.00 m / z to 600.00 m / z

  In Table 1, from the comparison between Example 1 and Comparative Example 1, when the content of normal paraffins having 19 to 23 carbon atoms is small and contains a large amount of cycloparaffins, the low temperature due to the addition of the EV low temperature fluidity improver (CFI1) It was confirmed that the effect of improving the properties was increased. Further, the low temperature fluidity improver having an improvement effect greater than that of Example 1 and Comparative Examples 2 and 3 is an EV type, and the addition of a surfactant system (CFI2) or a wax dispersant system (CFI3) does not significantly improve. It was confirmed. Furthermore, it was confirmed from Example 1 and Example 2 that the effect of improving the low-temperature properties was also great when a large amount of aromatics was contained.

Claims (1)

Consists of one or more light oil bases and an EV-based low temperature fluidity improver,
Contains a gas oil base that is hydrodesulfurized by mixing cracked gas oil with straight-run gas oil,
The normal paraffin content of 19 to 23 carbon atoms is 7.5 mass% or less, the cycloparaffins is 34 mass% or more, the aromatic content is 18 vol% or more, the alkylbenzenes are 10 mass% or more, and the bicyclic cycloparaffins are 11 mass% or more, and A light oil fuel composition having a sulfur content of 10 massppm or less.

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